PSLE Winnie had a box of white beads and purple beads in the ratio 13 : 7. She removed an equal number of white beads and purple beads from the box. The ratio of the number of white beads and purple beads left in the box became 8 : 3. What percentage of the beads were left in the box?
|
White beads |
Purple beads |
Difference |
Total |
Before |
13x5 = 65 u |
7x5 = 35 u |
6x5 = 30 u |
20x5 = 100 u |
Change |
- 17 u |
- 17 u |
|
|
After |
8x6 = 48 u |
3x6 = 18 u |
5x6 = 30 u |
11x6 = 66 u |
When Winnie removed an equal number of white beads and purple beads, the difference between the number of white beads and purple beads at first and in the end remains the same.
LCM of 6 and 5 is 30.
Percentage of the beads left in the box
=
66100 x 100%
= 3350 x 100%
= 66%
Answer: 66%